Latch mechanism

ABSTRACT

Latch mechanism having a lock cylinder which provides an actuator by which an exceptionally long retraction stroke of the latch bolt is effected in consequence of rotation of the cylinder through an arc of only 90*. A cavity which opens to the cylinder receiving bore accommodates the lock tumblers during withdrawal of the key from the cylinder in an unlocked position of cylinder rotation. The cavity also accommodates a bolt actuating cam on the cylinder at the time the cylinder is assembled with the lock body from the front thereof.

United States Patent 1191 Rubner Jan. 1, 1974 [54] LATCH MECHANISM 1,225,763 5/1917 Burke 292 175 In entor: go G. Rubner, M lwaukee, Wis- 2,585.643 2/l952 Feldmann 70/81 1 Assigneer igg and Stratton, Wauwatosa, Primary Examiner-Albert G. Craig, Jr.

Attorneylra Milton Jones [22] Filed: Jan. 21, 1972 211 App]. NO.2 219,644 [57] ABSTRACT Latch mechanism having a lock cylinder which pro- 52 us. c1 70/81 70/106 70/369 vides an actuator by whih exceptimally 292/i69 29271316 traction stroke of the latch bolt is effected in conse- 1511 1m. 01 E05!) 65/02 quence of rotation 0f the cylinder thmugh arc [581 Field of Search /81 106 144 only A cavity which Opens the Cylinder receiv- 70/l56 I62 I69 173 6 i ing bore accommodates the lock tumblers during with- 292163 169 175 DIG. drawal of the key from the cylinder in an unlocked position of cylinder rotation. The cavity also accommo- [56] References Cited dates a bolt actuating cam on the cylinder at the time the cylinder is assembled with the lock body from the UNITED STATES PATENTS from thereof 3,l4l,3l9 7/1964 Schlagc 70/81 1,656.275 1/1928 Hurd 70/!62 14 Claims, 10 Drawing Figures PATENTEU JAN .1I974 SHEEI 1 BF 4 FIGJ.

PATENTED JAN 1 4 amazon;

LATCH MECHANISM This invention relates to latch mechanisms, and has more particular reference to locking type latch mechanisms such as are commonly used on the glove compartment doors of automotive vehicles.

One of the main objectives of the invention resides in the provision of a latch mechanism wherein rotation of an actuator only one-quarter of a revolution is translated into motion of a latch bolt through an exceptionally long retraction stroke.

Another object of the invention is to provide a latch mechanism wherein the actuator comprises a lock cylinder having an unlocked key withdrawing position at which the lock tumblers can be momentarily accommodated in an elongated cavity in the bore of the lock body as the key is removed, and which cavity also accommodates the bolt actuating cam on the rear of the cylinder during assembly of the latter into the lock body from the front thereof.

Still another purpose of the invention is to provide a latch mechanism with a body having a tubular chamber at its rear in which the latch bolt operates, and wherein one wall of the chamber has an opening therein to enable the bolt spring to be passed therethrough and assembled between opposing spring seats on the bolt and chamber after the bolt is in a subassembled position therein, and wherein preformed stops on the bolt engage a wall of the chamber to prevent displacement of the bolt from said subassembly under the spring force acting thereon.

With these observations and objectives in mind, the manner in which the invention achieves its purpose will be appreciated from the following description and the accompanying drawings, which exemplify the invention, it being understood that changes may be made in the specific apparatus disclosed herein without departing from the essentials of the invention set forth in the appended claims.

The accompanying drawings illustrate one complete example of an embodiment of the invention constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:

FIG. 1 is an enlarged fragmentary section-al view through the door of an automobile glove compart-ment showing the latch mechanism of this invention in place on the door;

FIG. la is a sectional view taken through the mechanism on the line la-la in FIG. 2;

FIG. 2 is a rear view of the mechanism with portions of the lock body broken away;

FIG. 3 is a sectional view taken on the line 33 in FIG. 2;

FIG. 4 is a perspective view of the latch mechanism, showing the lock cylinder and the latch bolt removed from the lock case;

FIG. 4a is a view looking into the front of the lock case, with the cylinder and front bearing member removed therefrom;

FIG. 5 is a perspective view of the latch bolt per se, viewing the same from the rear;

FIG. 6 is a more or less diagrammatic view taken generally on line 6-6 in FIG. 1, showing the position of 6 FIG. 7 is a view similar to FIG. 6, but showing the cylinder in an unlocked key removing position displaced 90 from its locked position and establishing initial contact between its driver and the driven part on the bolt; and

FIG. 8 is a view similar to FIG. 6, but illustrating how the driver engages surfaces on the driven part located farther from the cylinder axis during bolt retracting rotation of the cylinder.

Referring now to the accompanying drawings, the numeral 10 generally designates the body of a latch mechanism embodying this invention. The body has a bore 11 which opens to its front and to a tubular bolt receiving chamber at its rear. The chamber is disposed with its axis crosswise of the bore. A cylindrical actuator 13 is rotatably received in the bore, and its rear end portion projects into the chamber 12 and has a cam 14 thereon. The actuator projects from the front of the bodyand has an enlarged head 9 thereon which carries a knob 15 to facilitate rotation of the actuator.

Rotation of the actuator effects retracting motion of an elongated latch bolt 16 in chamber 12, against the action of a bolt spring 17, from a normally projected position at which one end portion 18 of the bolt can be engaged with a keeper l9.

Mounting flanges 20 on the body project from opposite sides thereof to provide for securement of the latch mechanism to the door 21 of a glove compartment 22 on the instrument panel 23 of an automobile. The flanges 20 engage the rear of an inner door panel part 24 to which they are secured by screws or the like. The knob 15, of course, is accessible at the front of the door for manual actuation. The door has been shown as mounted for pivotal motion about a horizontal axis adjacent to its lower edge, and the latch mechanism as being secured thereto adjacent to its upper edge. However, other mountings for the door are possible, and the bolt need not necessarily be slidable vertically up and down, as herein shown. In fact, the mechanism can even be mounted on the instrument panel alongside the free edge of the door for cooperation with a door carried keeper.

As seen, however, the latch body is disposed with the axis of its tubular bolt receiving chamber 12 in a vertical position when the door is latched closed. Hence, the walls of the chamber constrain the bolt to endwise translatory motion (up and down), along a path which is parallel to the chamber axis and crosswise of the axis of the actuator 13, toward and from its operative position at which the projecting end portion 18 of the bolt engages behind the downwardly projecting keeper 19 on the instrument panel.

The latch bolt 16 is generally rectangular in cross section, and the chamber has a similar cross sectional shape, with flat walls that are contiguous to those of the bolt so as to constrain it to the desired endwise translatory motion. The bolt spring 17 is confined between opposing seats 26 and 27 on the bolt and the rear wall 28 of the chamber, respectively. The seat 27 projects forwardly from the wall 28 at the lower end thereof and the seat 26 is formed on the upper end portion of the bolt, which has a vertically extending recess 29 in its back to accommodate the spring 17. The recess 29 is shaped to also accommodate the lower spring seat 27, and it has a length sufficient to enable the bolt to be inserted into the chamber through the open bottom thereof during assembly without interference from the spring seat 27.

An important feature of this invention resides in the provision of preformed stops 30 on the opposite sides of the bolt at its bottom, which are engageable with the lower edges of the opposite side walls 31 of the chamber at the time the bolt is subassembled with the lock body, to prevent upward displacement of the bolt from the chamber 12 under the force of the bolt spring 17. Heretofore, in some compartment door latch constructions where the bolt and its spring had to be assembled into the top of a similar bolt chamber, the stops on the lower end of the bolt could only be formed by staking, after assembly of the bolt and spring into the chamber.

According to this invention, however, the bolt is subassembled with the lock body by inserting its keeper engaging end into the lower end of the bolt chamber. The spring 17 is next assembled, and for this purpose, the rear wall 28 of the chamber is provided with a vertically elongated opening 32 which registers with the recess 29 in the back of the bolt, and through which opening the bolt spring 17 can be passed to its properly assembled position between seats 26 and 27. It is important to note that the opening 32 is entirely above the spring seat 27, and that the spring must be compressed, and hence preloaded, in order to assemble it with the bolt.

From the description thus far, it will be seen that the provision of preformed stops 30 on the latch bolt represents a distinctly advantageous feature of this invention which eliminates time consuming stop forming staking operations such as were heretofore performed after assembly of the latch bolt into the chamber 12, and after assembly of the bolt spring in the bolt chamber.

While not absolutely essential to this invention, the actuator 13 is preferably in the form of a die cast lock cylinder having the cam 14 cast integrally therewith, and rotable in the body bore 11 between defined limits displaced l80 from one another. FIG. Ia shows the cylinder in its locking position at one limit of rotation, at which tumblers 35 carried by the cylinder are engageable in a tumbler slot 33 in the body. This limit of cylinder rotation is defined by the engagement of a lug 47 on the cylinder with one side of a stop 47' on the body. The tumblers are retractable from the slot 33 upon insertion of a proper key 36 into the key slot of the cylinder to free it for rotation in the clockwise direction (as viewed from the front) out of its locking position to its unlocked limit of rotation.

When the cylinder has been rotated by the key 36 to a first unlocked position displaced 90 from its locking position, the key can be withdrawn and the cylinder is free to be rotated back and forth between said first unlocked position and its unlocked limit of rotation defined by the engagement of the lug 47 on the cylinder with the other side of the body stop 47. It can do so because that side of the bore 11 opposite a tumbler relief cavity 34 is enlarged as at 34 to accommodate those end portions of the tumblers which project from the cylinder whenever the key is out of the cylinder. The projecting ends of the tumblers then cooperate with the cylinder lug 47 to limit unlocked rotation of the cylinder to 90 between the lug 47 and the stop 37 provided by one side of the tumbler relief cavity 34.

The elongated tumbler relief cavity 34 in the body, opens to its bore 11 and is disposed parallel to the axis thereof. It is provided to accommodate portions of the tumblers at one end thereof as the tumblers are thrust outwardly beyond the periphery of the cylinder by the hitting on the key during removal thereof from the cylinder in said first unlocked position thereof. This cavity opens rearwardly into the chamber 12, and it can also extend forwardly to the front of the lock body or to a point closely adjacent thereto for a purpose to be discussed shortly.

Rotation of the cylinder to its unlocked limit of rotation from the first unlocked position thereof effects retraction of the bolt 16 as a consequence of the engagement of the cam 14 on the rear of the lock cylinder with an abutment on the bolt in the form of a rack tooth 38 which projects into a large recess 39 in the front of the bolt, from one side of the recess. The cam 14 occupies a position contiguous to the upper flank of the tooth when the lock cylinder is in its first unlocked position seen in FIG. 7. It pushes down on the tooth to retract the bolt when the cylinder is rotated 90 in the clockwise direction to its unlocked limit of rotation, as seen in FIG. 8.

It is a feature of considerable importance that rotation of the cylinder a mere one-quarter turn (or less) can effect retracting motion of the latch bolt through an exceptionally long retraction stroke. This is made possible in part by the particular shape and length of the bolt driving cam, and by the rack tooth shape of the abutment 38 on the latch bolt with which the cam cooperates. However, it will be appreciated that the same long retraction stroke of the bolt can be effected by rotation of the cylinder through an arc of less than 90 if the cam 14 has the necessary additional length and the rack tooth 38 on the bolt is proportioned accordingly.

The rear of the lock cylinder projects into the bolt chamber 12 so as to dispose its bolt actuating cam 14 in the bolt cavity 39 for cooperation with the tooth 38 on the side ofthe cavity. The cam is in the nature of an arm that projects more or less radially to one side of the cylinder a substantial distance beyond its periphery. Its outer end portion is curved in such a manner as to assure initial contact between it and the upper flank of the tooth 38 at a location near the tip of the tooth (see FIG. 7). As the cylinder is rotated in the bolt retracting direction, the contact point between the cam and tooth moves progressively toward the root of the tooth and away from the axis of cylinder rotation, to thus increase the throw of the cam 14 and add distance to the retraction stroke of the bolt. The bolt is fully retracted when the cam has been carried 90 from its position at which it initially contacts the tooth 38 on the bolt (see FIG. 8). At this clockwise limit of cylinder rotation (shown in construction lines in FIG. 8), at which the bolt is fully retracted, the point of engagement between the cam and tooth 38 is spaced the greatest distance from the cylinder axis.

It is significant to note that it would be impossible to assemble the lock cylinder into the bore 11 from the front of the latch body if it were not for the fact that the tumbler relief cavity 34 is made deep enough (radially) as to provide a channel along which the outer end portion of the cam can pass to reach the recess in the front of the latch bolt.

As stated earlier, the channel provided by the tumbler relief cavity 34 can extend all the way forwardly to the front of the lock body, but in some cases it may be desirable to terminate it a slight distance short of the front of the body. In that event, the cam 14 can still be maneuvered into the bore and the cavity 34, as by tilting the cylinder somewhat out of coaxial relation to the bore axis.

The lock cylinder can be releasably held against forward displacement from its assembled position in the bore 11 by the engagement of a so-called retaining tumbler with the rear of a radially outwardly directed flange on a bearing member 41. The bearing member is shown as a stamping secured as by clinching, in a shallow counterbore in the mouth of the bore 11, and it has a cylindrical bearing surface 42 in which the front end portion of the lock cylinder is rotatably supported.

The bearing member 41 materially aids in supporting the lock cylinder for rotary motion in the bore 11, especially since much of the wall of the bore is cut away not only for the provision of the two tumbler receiving slots or cavities 33 and 34, but also for the bore enlargement 34' mentioned earlier, which provides a tumbler clearance space that must extend through an arc of considerably more than 90. Hence, the body wards between these tumbler relief cavities present angularly spaced bearing surfaces of limited area which extend only slightly more than one-half the circumference of the lock cylinder except at the rear of the bore 11. There, the rear portion of the cylinder is rotatably journalled in an axially short bearing portion 43 of the bore which, however, is cooperable with the bearing member 41 to afford adequate support for the cylinder.

As seen best in FIG. la, the bolt 16 has a horizontal ledge 45 thereon, beneath its tooth 38 and at the bottom of its recess 39. This ledge engages the underside of a cylindrical bolt locator 46 on the rear of the lock cylinder to define the projected position of the bolt seen in FIG. 6. The bolt locator 46 is situated rearwardly of the rotation arresting lug 47 on the cylinder, between said lug and the cam 14 on the extremity of the bolt locator.

In all positions of rotation of the cylinder in its bore, prior to engagement of the cam with the rack tooth 38, the bolt spring 17 presses the rear of the lock cylinder against the bearing portion 43 through the engagement of the ledge 45 on the bolt with the underside of the bolt locator 46. After the cam engages the rack tooth, the bolt spring then acts through the tooth and the cam to hold the rear of the cylinder in engagement with the bearing portion 43. Accordingly, the bolt spring serves as an anti-rattle device in that it acts through the bolt to take up the clearance between the rear of the cylinder and the wall of the bore II at one side thereof without interfering with rotation of the cylinder in the bore.

FIGS. 1a and 7 also show how a flat 49 on one side of the otherwise cylindrical bolt locating part 46 cooperates with the ledge 45 in the provision of a detent device to arrest rotation of the cylinder out of its locking position (FIG. 6) at its unlocked key withdrawing position seen in FIG. 7, at which the cylinder is displaced 90 from its locking position. The flat 49 is located on the side of the part 46 substantially diametrically opposite that from which the cam 14 projects, so that it will flatwise engage the ledge 45 on the bolt substantially at the time the cam is brought into initial engagement with the tooth 38 on the bolt (FIG. 7). The detent device thus provided, of course, is rendered effective under the force of the bolt spring 17.

Because of the above described antirattle and detent features, of course, the preformed stops 30 on the bottom of the bolt must not engage the bottom edges of the walls of the bolt receiving chamber after the cylinder has been assembled into the lock body. The stops 30 are provided only to enable the bolt and its spring to be subassembled in the bolt chamber, and thus allow handling of these subassembled components during manufacture without danger of them becoming displaced before the cylinder is installed in the body bore.

It will also be appreciated that the bolt spring 17 will be effective to automatically return the lock cylinder to its position seen in FIG. 7, upon release of the knob 15 when the cylinder is in its bolt retracted position seen in FIG. 8. The spring, of course, also returns the bolt to its projected position at that time.

Attention is again directed to FIG. 1a where, in the fully retracted position of the bolt shown in broken lines, it will be seen that the compressed length of the bolt spring 17 is greater than the length (height) of the recess 32 in the back wall of the bolt receiving chamber 12. In fact, the spring seats 26 and 27 are so located that in any working position of the bolt, the top edge 50 of the recess will always be below the spring seat 26 on the upper portion of the bolt. The bottom edge 50' of the recess is located a fixed distance above the lower spring seat 27. Hence, one or more of the convolutions of the spring at its upper end will always be disposed above the upper edge 50 of the recess in the retracted position of the bolt, and substantially one-half the length of the spring will be disposed above the edge 50 of the recess when the bolt is in its projected position.

This provides excellent assurance against accidental displacement of the bolt spring through the recess 32. In fact, if removal of the spring should become necessary, such removal will entail either the use of a special tool inserted into the recess 32, or manual depression of the bolt to a position inwardly of the chamber 12 beyond the normally retracted position of the bolt to bring the upper end of the spring below the edge 50 of the recess.

It is significant to observe that the lock cylinder 13 has portions at its opposite ends which extend radially outwardly to distances considerably beyond the periphery of the tumbler receiving portion of the cylinder therebetween. The head-like enlargement 9 at the projecting forward end of the cylinder of course, prevents assembly of the cylinder into the bore 11 from the rear of the latch body. The long arm of the cam 14 similarly prevents insertion of the cylinder into its bore from the front of the latch body, except when the cylinder is oriented to bring its cam arm into register with the tumbler relief slot 34. If desired, the bearing member 41 can be provided with an opening 52 therein to facilitate insertion of the cam into the relief slot 34.

From the foregoing description, together with the accompanying drawings, it will be readily apparent to those skilled in the art that this invention provides door latch mechanism which is unique in that it assures an unusually long retraction stroke for the latch bolt in consequence of only one-quarter of a revolution of the bolt actuator; and which mechanism features an exceptionally simple way of assembling the latch bolt and its spring.

Those skilled in the art will appreciate that the invention can be embodied in forms other than as herein disclosed for purposes of illustration.

The invention is defined by the following claims:

1. Door latch mechanism having a body with a bore opening to its front and to a chamber at its rear, and wherein retracting motion of a normally projected latch bolt in said chamber is effected in consequence of rotaty motion of an actuator from one position to another in said bore, characterized by the following:

A. said chamber having walls which constrain the bolt to translatory motion toward and from its projected position along a path crosswise of the bore axis;

B. said chamber being substantially larger than the bore in dimensions crosswise of the bore;

C. means drivingly connected with the rear of the actuator and located in said chamber providing a bolt retracting cam through which said retracting motion of the bolt is effected, said cam projecting a substantial distance to one side of the actuator axis and beyond the wall of the bore so as to produce a long retraction stroke for the bolt;

D. said actuator comprising a lock cylinder having key operable tumblers to lock the cylinder against rotation to said other position thereof;

E. and the rear of the lock cylinder projecting into said chamber, and together with the bolt retracting cam comprising a one-piece casting.

2. Door latch mechanism having a body with a bore opening to its front and to a chamber at its rear, and wherein retracting motion of a normally projected latch bolt in said chamber is effected in consequence of rotary motion of an actuator from one position to another in said bore, characterized by the following:

A. said chamber having walls which constrain the bolt to translatory motion toward and from its projected position along a path crosswise of the bore axis;

B. said chamber being substantially larger than the bore in dimensions crosswise of the bore;

C. means drivingly connected with the rear of the actuator and located in said chamber providing a bolt retracting cam through which said retracting motion of the bolt is effected, said cam projecting a substantial distance to one side of the actuator axis and beyond the wall of the bore so as to produce a long retraction stroke for the bolt;

D. said actuator comprising a lock cylinder having key operable tumblers to lock the cylinder against rotation to said other position thereof;

E. the body having a tumbler relief cavity opening to said bore and extending lengthwise thereof, in register with the lock tumblers in an unlocked key withdrawing position of cylinder rotation;

F. and said tumbler relief cavity providing a channel which opens to said chamber and extends forwardly to the front portion of the body, to accommodate said cam during assembly of the cylinder into the bore from the front of the body.

3. The door latch mechanism of claim 2, wherein said channel also opens to the front of the body.

4. Door latch mechanism having a body with a bore opening to its front, a normally projected latch bolt, and a bolt actuator in the bore to effect retracting motion of the bolt in consequence of rotary motion of the actuator from one position to another, characterized by the following:

A. means on the rear of the body defining a tubular chamber in which the bolt operates and in which the bolt is constrained to translatory motion along a path crosswise of the bore axis, one end portion of the bolt normally projecting from one end of the tubular chamber to one side of the body, and the bolt being insertable into the tubular chamber for assembly therewith from the other end of the chamber;

B. abutment means defining spaced apart opposing spring seats on the bolt and chamber at a location adjacent to one chamber wall;

C. a bolt spring confined between said seats to yieldingly hold the bolt projected;

D. said one chamber wall having an opening therein through which the spring can be inserted into the chamber to an assembled position between said seats;

E. abutment means on said other end portion of the tubular chamber;

F. and preformed abutment means on the bolt engageable with said last named abutment means on the tubular chamber to hold the bolt against displacement from its chamber even though the bolt actuator is removed from the latch body.

5. Door latch mechanism having a body with a bore opening to its front, a normally projected latch bolt, and a bolt actuator in the bore to effect retracting motion of the bolt in consequence of rotary motion of the actuator from one position to another, characterized by the following:

A. means on the rear of the body defining a chamber in which the bolt operates and in which the bolt is constrained to translatory motion along a path crosswise of the bore axis, one end portion of the bolt normally projecting from the chamber to one side of the body;

B. abutment means defining spaced apart opposing spring seats on the bolt and chamber at a location adjacent to one wall thereof;

C. a bolt spring confined between said seats to yieldingly hold the bolt projected;

D. said one chamber wall having an opening therein through which the spring can be inserted into the chamber to an assembled position between said seats;

E. and said spring seats being so located with respect to said opening through which the spring is insertable as to be covered by portions of said one chamber wall in all normal positions of the bolt in said chamber.

6. The door latch mechanism of claim 5, wherein said bolt retracting motion is effected by cooperating elements on the actuator and the bolt, one of said elements comprising a driver integral with the actuator, and the other element being fixed with respect to the bolt.

7. The door latch mechanism of claim 5 further characterized by:

A. said bolt extending lengthwise across the bore axis;

B. said bore opening inwardly to said chamber and to a recess in the front of the bolt substantially wider than the bore diameter;

C. and said bolt retracting motion being effected by a cam on the rear of said actuator, which cam projects into the bolt recess and extends radially a substantial distance beyond one side of the actuator to travel in an orbit substantially larger in diameter than said bore.

8. The door latch mechanism of claim 5, further characterized by:

A. said bolt having a ledge thereon;

B. the bolt actuator having a locator on its rear which is engaged by the ledge on the bolt to define the projected position of the bolt.

C. and the bolt spring acting upon the actuator through the engagement of said locator thereon by the ledge on the bolt, to press the rear of the actuator against the wall of said bore and thereby prevent rattling of the actuator in its bore.

9. Door latch mechanism having a body with a bore opening to its front, and a normally projected latch bolt, characterized by the following:

A. a bolt actuator comprising a key controlled lock cylinder in the bore rotatable in one direction through an arc of 90 from a locked position of rotation to an unlocked key withdrawing position of rotation, to impart retracting motion to the bolt only during rotationof the cylinder another 90 in the same direction;

B. means on the rear of the body defining a chamber in which the bolt operates and in which the bolt is constrained to translatory motion along a path crosswise of the bore axis, one end portion of the bolt normally projecting from the chamber to one side of the body;

C. abutment means defining spaced apart opposing spring seats on the bolt and chamber at a location adjacent to one wall thereof;

D. a bolt spring confined between said seats to yieldingly hold the bolt projected;

,5. said chamber wall having an opening therein through which the spring can be inserted into the chamber to an assembled position between said seats;

F. the bolt having a ledge thereon;

G. the cylinder having a locator on its rear which is engaged by the ledge on the bolt to define its projected position;

H. the bolt spring acting upon the cylinder through the engagement of its locator by the ledge on the bolt, to press the rear of the cylinder against the wall of said bore and thereby prevent rattling of the cylinder in the bore;

. and cooperating detent means on the locator and ledge to arrest said rotary motion of the cylinder at said unlocked key withdrawing position thereof.

10. The door latch mechanism of claim 9, further characterized by:

A. said bolt locator being cylindrical and coaxial with the lock cylinder;

B. and said detent means comprises a flat on the cylindrical surface of the locator.

11. Door latch mechanism having a body with a bore opening to its front and to a chamber at its rear, a latch bolt in said chamber biased to an operative position projecting from one portion of the chamber for engagement with a keeper, and where insertion of a proper key into a lock cylinder in the bore releases the cylin-' der for rotation to a position at which the latch-bolt is retracted, characterized by:

A. the cylinder being a casting having a head thereon adjacent to the front of the body, which head is of a size to prevent assembly of the cylinder into the bore from the rear of the body;

B. the body having a tumbler relief cavity opening to its bore to enable removal of the key from the cylinder in an unlocked position of cylinder rotation;

C. a cam on the rear of the cylinder to engage a part on the bolt and effect said retraction thereof;

D. said cam comprising an arm which is an integral part of the cylinder casting and which extends radi ally a distance from the cylinder axis substantially greater than the radius of the bore;

E. and said tumbler relief cavity providing a channel leading to the bolt chamber from the front portion of the body, along which the cam arm can pass to enable assembly of the cylinder into the bore.

12. Door latch mechanism having a body with a bore opening to its front and to a chamber at its rear, and wherein retracting motion of a normally projected latch bolt in said chamber, against spring bias, is effected in consequence of rotary motion of an actuator from one position to another in said bore, characterized by the following:

A. said chamber having walls which constrain the bolt to translatory motion toward and from its projected position along a path crosswise of the bore axis;

B. said chamber being substantially larger than the bore in dimensions crosswise of the bore;

C. said bolt having a recess therein which opens forwardly toward the actuator;

D. the rear of the actuator projecting into said recess to be engageable by one wall thereof to thereby define the projected position of the bolt;

E. means fixed to the rear of the actuator and located in said bolt recess providing a bolt retracting cam through which retracting motion of the bolt is effected, said cam projecting a substantial distance to one side of the actuator axis and beyond the wall of the bore so as to produce a long retraction stroke for the bolt;

F. said actuator comprising a lock cylinder having key operable tumblers to lock the cylinder against rotation to said other position thereof;

G. cooperating detent means on the rear of the cylinder and said wall of the recess in the latch bolt, rendered effective under the force of the spring bias on the bolt to arrest rotation of the cylinder at a key removing position partway toward its said other position;

H. and said bolt retracting cam being operable to effect retraction of the bolt during rotation of the cylinder beyond its said key removing position.

13. Door latch mechanism having a body with a bore opening to its front and to a chamber at its rear, and wherein retracting motion of a normally projected latch bolt in said chamber, against spring bias, is effected in consequence of rotary motion of an actuator from one position to another in said bore, characterized by the following:

A. said chamber having walls which constrain the bolt to translatory motion toward and from its projected position along a path crosswise of the bore axis;

B. said chamber being substantially larger than the bore in dimensions crosswise of the bore; C. said bolt having a recess therein which opens forwardly toward the actuator;

D. the rear of the actuator projecting into said recess to be engageable by one wall thereof to thereby define the projected position of the bolt;

E. means fixed to the rear of the actuator and located in said bolt recess providing a bolt retracting cam through which retracting motion of the bolt is effected, said cam projecting a substantial distance to one side of the actuator axis and beyond the wall of the bore so as to produce a long retraction stroke for the bolt;

F. an abutment on the latch bolt located on the bottom of its recess, adjacent to a side wall thereof which is disposed lengthwise of the path of bolt motion, and to pass behind the rear of the actuator during retracting motion of the bolt;

said long retraction stroke of the bolt is effected during rotation of the actuator through an arc of not more than 

1. Door latch mechanism having a body with a bore opening to its front and to a chamber at its rear, and wherein retracting motion of a normally projected latch bolt in said chamber is effected in consequence of rotaty motion of an actuator from one position to another in said bore, characterized by the following: A. said chamber having walls which constrain the bolt to translatory motion toward and from its projected position along a path crosswise of the bore axis; B. said chamber being substantially larger than the bore in dimensions crosswise of the bore; C. means drivingly connected with the rear of the actuator and located in said chamber providing a bolt retracting cam through which said retracting motion of the bolt is effected, said cam projecting a substantial distance to one side of the actuator axis and beyond the wall of the bore so as to produce a long retraction stroke for the bolt; D. said actuator comprising a lock cylinder having key operable tumblers to lock the cylinder against rotation to said other position thereof; E. and the rear of the lock cylinder projecting into said chamber, and together with the bolt retracting cam comprising a one-piece casting.
 2. Door latch mechanism having a body with a bore opening to its front and to a chamber at its rear, and wherein retracting motion of a normally projected latch bolt in said chamber is effected in consequence of rotary motion of an actuator from one position to another in said bore, characterized by the following: A. said chamber having walls which constrain the bolt to translatory motion toward and from its projected position along a path crosswise of the bore axis; B. said chamber being substantially larger than the bore in dimensions crosswise of the bore; C. means drivingly connected with the rear of the actuator and located in said chamber providing a bolt retracting cam through which said retracting motion of the bolt is effected, said cam projecting a substantial distAnce to one side of the actuator axis and beyond the wall of the bore so as to produce a long retraction stroke for the bolt; D. said actuator comprising a lock cylinder having key operable tumblers to lock the cylinder against rotation to said other position thereof; E. the body having a tumbler relief cavity opening to said bore and extending lengthwise thereof, in register with the lock tumblers in an unlocked key withdrawing position of cylinder rotation; F. and said tumbler relief cavity providing a channel which opens to said chamber and extends forwardly to the front portion of the body, to accommodate said cam during assembly of the cylinder into the bore from the front of the body.
 3. The door latch mechanism of claim 2, wherein said channel also opens to the front of the body.
 4. Door latch mechanism having a body with a bore opening to its front, a normally projected latch bolt, and a bolt actuator in the bore to effect retracting motion of the bolt in consequence of rotary motion of the actuator from one position to another, characterized by the following: A. means on the rear of the body defining a tubular chamber in which the bolt operates and in which the bolt is constrained to translatory motion along a path crosswise of the bore axis, one end portion of the bolt normally projecting from one end of the tubular chamber to one side of the body, and the bolt being insertable into the tubular chamber for assembly therewith from the other end of the chamber; B. abutment means defining spaced apart opposing spring seats on the bolt and chamber at a location adjacent to one chamber wall; C. a bolt spring confined between said seats to yieldingly hold the bolt projected; D. said one chamber wall having an opening therein through which the spring can be inserted into the chamber to an assembled position between said seats; E. abutment means on said other end portion of the tubular chamber; F. and preformed abutment means on the bolt engageable with said last named abutment means on the tubular chamber to hold the bolt against displacement from its chamber even though the bolt actuator is removed from the latch body.
 5. Door latch mechanism having a body with a bore opening to its front, a normally projected latch bolt, and a bolt actuator in the bore to effect retracting motion of the bolt in consequence of rotary motion of the actuator from one position to another, characterized by the following: A. means on the rear of the body defining a chamber in which the bolt operates and in which the bolt is constrained to translatory motion along a path crosswise of the bore axis, one end portion of the bolt normally projecting from the chamber to one side of the body; B. abutment means defining spaced apart opposing spring seats on the bolt and chamber at a location adjacent to one wall thereof; C. a bolt spring confined between said seats to yieldingly hold the bolt projected; D. said one chamber wall having an opening therein through which the spring can be inserted into the chamber to an assembled position between said seats; E. and said spring seats being so located with respect to said opening through which the spring is insertable as to be covered by portions of said one chamber wall in all normal positions of the bolt in said chamber.
 6. The door latch mechanism of claim 5, wherein said bolt retracting motion is effected by cooperating elements on the actuator and the bolt, one of said elements comprising a driver integral with the actuator, and the other element being fixed with respect to the bolt.
 7. The door latch mechanism of claim 5 further characterized by: A. said bolt extending lengthwise across the bore axis; B. said bore opening inwardly to said chamber and to a recess in the front of the bolt substantially wider than the bore diameter; C. and said bolt retracting motion being effected by a cam on the rear of saId actuator, which cam projects into the bolt recess and extends radially a substantial distance beyond one side of the actuator to travel in an orbit substantially larger in diameter than said bore.
 8. The door latch mechanism of claim 5, further characterized by: A. said bolt having a ledge thereon; B. the bolt actuator having a locator on its rear which is engaged by the ledge on the bolt to define the projected position of the bolt; C. and the bolt spring acting upon the actuator through the engagement of said locator thereon by the ledge on the bolt, to press the rear of the actuator against the wall of said bore and thereby prevent rattling of the actuator in its bore.
 9. Door latch mechanism having a body with a bore opening to its front, and a normally projected latch bolt, characterized by the following: A. a bolt actuator comprising a key controlled lock cylinder in the bore rotatable in one direction through an arc of 90* from a locked position of rotation to an unlocked key withdrawing position of rotation, to impart retracting motion to the bolt only during rotation of the cylinder another 90* in the same direction; B. means on the rear of the body defining a chamber in which the bolt operates and in which the bolt is constrained to translatory motion along a path crosswise of the bore axis, one end portion of the bolt normally projecting from the chamber to one side of the body; C. abutment means defining spaced apart opposing spring seats on the bolt and chamber at a location adjacent to one wall thereof; D. a bolt spring confined between said seats to yieldingly hold the bolt projected; E. said chamber wall having an opening therein through which the spring can be inserted into the chamber to an assembled position between said seats; F. the bolt having a ledge thereon; G. the cylinder having a locator on its rear which is engaged by the ledge on the bolt to define its projected position; H. the bolt spring acting upon the cylinder through the engagement of its locator by the ledge on the bolt, to press the rear of the cylinder against the wall of said bore and thereby prevent rattling of the cylinder in the bore; I. and cooperating detent means on the locator and ledge to arrest said rotary motion of the cylinder at said unlocked key withdrawing position thereof.
 10. The door latch mechanism of claim 9, further characterized by: A. said bolt locator being cylindrical and coaxial with the lock cylinder; B. and said detent means comprises a flat on the cylindrical surface of the locator.
 11. Door latch mechanism having a body with a bore opening to its front and to a chamber at its rear, a latch bolt in said chamber biased to an operative position projecting from one portion of the chamber for engagement with a keeper, and where insertion of a proper key into a lock cylinder in the bore releases the cylinder for rotation to a position at which the latch bolt is retracted, characterized by: A. the cylinder being a casting having a head thereon adjacent to the front of the body, which head is of a size to prevent assembly of the cylinder into the bore from the rear of the body; B. the body having a tumbler relief cavity opening to its bore to enable removal of the key from the cylinder in an unlocked position of cylinder rotation; C. a cam on the rear of the cylinder to engage a part on the bolt and effect said retraction thereof; D. said cam comprising an arm which is an integral part of the cylinder casting and which extends radially a distance from the cylinder axis substantially greater than the radius of the bore; E. and said tumbler relief cavity providing a channel leading to the bolt chamber from the front portion of the body, along which the cam arm can pass to enable assembly of the cylinder into the bore.
 12. Door latch mechanism having a body with a bore opening tO its front and to a chamber at its rear, and wherein retracting motion of a normally projected latch bolt in said chamber, against spring bias, is effected in consequence of rotary motion of an actuator from one position to another in said bore, characterized by the following: A. said chamber having walls which constrain the bolt to translatory motion toward and from its projected position along a path crosswise of the bore axis; B. said chamber being substantially larger than the bore in dimensions crosswise of the bore; C. said bolt having a recess therein which opens forwardly toward the actuator; D. the rear of the actuator projecting into said recess to be engageable by one wall thereof to thereby define the projected position of the bolt; E. means fixed to the rear of the actuator and located in said bolt recess providing a bolt retracting cam through which retracting motion of the bolt is effected, said cam projecting a substantial distance to one side of the actuator axis and beyond the wall of the bore so as to produce a long retraction stroke for the bolt; F. said actuator comprising a lock cylinder having key operable tumblers to lock the cylinder against rotation to said other position thereof; G. cooperating detent means on the rear of the cylinder and said wall of the recess in the latch bolt, rendered effective under the force of the spring bias on the bolt to arrest rotation of the cylinder at a key removing position partway toward its said other position; H. and said bolt retracting cam being operable to effect retraction of the bolt during rotation of the cylinder beyond its said key removing position.
 13. Door latch mechanism having a body with a bore opening to its front and to a chamber at its rear, and wherein retracting motion of a normally projected latch bolt in said chamber, against spring bias, is effected in consequence of rotary motion of an actuator from one position to another in said bore, characterized by the following: A. said chamber having walls which constrain the bolt to translatory motion toward and from its projected position along a path crosswise of the bore axis; B. said chamber being substantially larger than the bore in dimensions crosswise of the bore; C. said bolt having a recess therein which opens forwardly toward the actuator; D. the rear of the actuator projecting into said recess to be engageable by one wall thereof to thereby define the projected position of the bolt; E. means fixed to the rear of the actuator and located in said bolt recess providing a bolt retracting cam through which retracting motion of the bolt is effected, said cam projecting a substantial distance to one side of the actuator axis and beyond the wall of the bore so as to produce a long retraction stroke for the bolt; F. an abutment on the latch bolt located on the bottom of its recess, adjacent to a side wall thereof which is disposed lengthwise of the path of bolt motion, and to pass behind the rear of the actuator during retracting motion of the bolt; G. a cam surface on said abutment which is engageable by the radially outer portion of the cam and which slopes toward the actuator axis, in the direction of bolt retracting motion; H. and said radially outer portion of the cam being convexly curved and adapted to contact said cam surface at progressively greater distances from the axis of the actuator as the latter is rotated toward said other position thereof, to thus assure a long retraction stroke for the bolt.
 14. The door latch mechanism of claim 13, wherein said long retraction stroke of the bolt is effected during rotation of the actuator through an arc of not more than 90*. 